Method of splitting of brittle materials with trenching technology

ABSTRACT

One aspect of the invention relates to a method for splitting an object made of brittle material into at least two pieces. The object has a first flat surface and a second flat surface opposite to each other. The method includes etching at least one trench in at least one of the surfaces so as to form at least one line on the surface. The method also includes splitting the object into separate pieces along the line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Utility Patent Application claims priority to German PatentApplication No. DE 10 2005 046 479.3, filed on Sep. 28, 2005, which isincorporated herein by reference.

BACKGROUND

One aspect of the present invention relates to methods for splittingobjects made of brittle materials and, in particular, methods forsplitting semiconductor wafers made of brittle materials.

Known in the art are methods for cutting and splitting objects made ofbrittle materials such as glass, sapphire, quartz, silicon, germanium,ceramic, and many others. An important industrial application of brittlematerial cutting is semiconductor manufacturing where one semiconductorwafer is diced into many separate, smaller pieces.

Brittle material cutting and splitting methods range from conventionalsawing to splitting with mechanical force or with a scribing/abrasiontool, to thermal splitting with or without a thermal shock process,laser ablation, or a combination of any of the above. US 2004/0251290A1, provides, in the introduction section thereof, a summary of some ofthe well-known conventional brittle material splitting methods.

Among the many limitations of the conventional methods are inefficiencyand low quality of edges obtained with these methods. To improve theseaspects, EP 0 633 867 B 1 discloses a method for splitting bodies ofnon-metallic brittle material, such as glass, by scoring a certain pointof the material to a certain depth followed by splitting it with somesplitting method. The scoring, however, inevitably causes an “initialdamage” to the material. Although claimed to provide for increasingsplitting speed and improving edge quality, this method may neverthelessrequire an “initial damage” to be made to the object of brittle materialat the start of each splitting which may cause intolerable problems. Forexample, in certain applications, such as semiconductor wafer dicing,many such “initial damages” are required due to the requirement ofcutting the wafer in both X and Y directions. This is very timeconsuming and for small dies not practicable.

In addition due to the very “initial damage,” the quality of the edge(s)of the separate wafer pieces or devices finally produced would suffer;besides, low-quality edge(s) would in turn degrade the pieces or devicesin terms of mechanical properties, such as the robustness and electricalproperties, such as the electrical leakage current of the device.

Thus, a method for splitting objects of brittle materials that is fast,produces high quality edges for the end pieces, and causes little or nomechanical and electrical property loss to the end pieces would be auseful improvement.

SUMMARY

One aspect of the invention provides a method for splitting an objectmade of brittle material into at least two pieces. The object has afirst flat surface and a second flat surface opposite to each other. Themethod includes etching at least one trench in at least one of thesurfaces so as to form at least one line on the surface. The method alsoincludes splitting the object into separate pieces along the line.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present invention and are incorporated in andconstitute a part of this specification. The drawings illustrate theembodiments of the present invention and together with the descriptionserve to explain the principles of the invention. Other embodiments ofthe present invention and many of the intended advantages of the presentinvention will be readily appreciated as they become better understoodby reference to the following detailed description. The elements of thedrawings are not necessarily to scale relative to each other. Likereference numerals designate corresponding similar parts.

FIG. 1 is a cross sectional view of an example object made of brittlematerial.

FIG. 2 is a perspective view of a part of the object being split using afirst embodiment of the method of the present invention.

FIG. 3 is a perspective view of a part of the object being split using asecond embodiment of the method of the present invention.

FIG. 4 is a perspective view of a part of the object being split using athird embodiment of the method of the present invention.

FIG. 5 is a perspective view of a part of the object being split using afourth embodiment of the method of the present invention.

FIG. 6 is a perspective view of a part of the object being split using afifth embodiment of the method of the present invention.

FIG. 7 is a perspective view of a part of the object being split using asixth embodiment of the method of the present invention.

FIG. 8 is a cross sectional view of a part of the object being splitusing a sixth embodiment of the method of the present invention.

FIG. 9 is a cross sectional view of an example edge formed by the methodof the present invention.

DETAILED DESCRIPTION

In the following Detailed Description, reference is made to theaccompanying drawings, which form a part hereof, and in which is shownby way of illustration specific embodiments in which the invention maybe practiced. In this regard, directional terminology, such as “top,”“bottom,” “front,” “back,” “leading,” “trailing,” etc., is used withreference to the orientation of the Figure(s) being described. Becausecomponents of embodiments of the present invention can be positioned ina number of different orientations, the directional terminology is usedfor purposes of illustration and is in no way limiting. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope of thepresent invention. The following detailed description, therefore, is notto be taken in a limiting sense, and the scope of the present inventionis defined by the appended claims.

One embodiment of method is applicable to any object made of either asingle brittle material or a combination of different materials. Theobject is in one case flat and has two flat surfaces opposite to eachother.

The method one case is applicable to processed semiconductor wafer. Thisis typically made from a substrate of brittle material with variousadditional layers such as Oxide, metal, silicone glass etc. The piecesobtained by splitting a processed semiconductor wafer usually arereferred to as “devices” or “chips”.

One aspect of the method is to combine trench etching with any ofbrittle material cutting or splitting methods. Specifically, the methodfirstly etches a trench or a plurality of trenches in at least one ofthe two opposite flat surfaces of the object, the trench or trenchesthus defining a line or a plurality of lines on the surface(s) etched;then the method splits the object into at least two pieces along thedefined line(s) with any of brittle material splitting methods. Thesemethods include, but are not limited to, splitting with mechanicalforce, scribing/abrasion methods, thermal splitting with or without athermal shock process, laser ablation, etcetera. The edges of theseparated pieces correspond to the defined line(s) along which thesplitting takes place.

In one embodiment of the present invention, trench etching plays a role.Etching removes a part of the brittle material along the line(s) createdby the etched trench(es) and therefore decreases the wafer strengthalong the line(s). Compared with methods for splitting the objectwithout trench etching prior to the final splitting, this weakeningenables the final splitting to be performed in many directions includingcrossing a previously split line and at a higher speed, with better edgequality and under a better control.

So etching trenches in the surface(s) of an object of brittle materialprior to splitting the object provides one aspect of the presentinvention with advantages over the prior art methods.

Firstly, one aspect of the invention saves a great deal of time. Insplitting the object into many pieces, the prior art method needs tomake an initial defect at the start of each cut. In embodiments thepresent invention, a plurality of trenches in the same or in differentdirections can be formed at the same time. Thus, in examples such assemiconductor wafer dicing where a wafer usually needs to be diced intosmall pieces in both X and Y directions, the “initial damage” must beprecisely made, not only at the wafer edge in the X direction, but alsoat each chip in the Y direction. This is extremely time consuming to theextent that for small dies it is not possible. So, embodiments of themethod of the present invention are more efficient than the prior artmethod.

Secondly, trench etching weakens the substrate material in the areawhere splitting is to be performed. This reduces the tendency for stressinherent in the substrate to change the direction of splitting, forexample in the wafer edge regions, and it also enables splitting theobject in directions other than the crystal alignment, which providesmore splitting options. For example the outer edge or a portion of thewafer may be removed. This has important applications for somesemiconductor manufacturing processes.

Thirdly, embodiments of the present invention improve the quality of theedge or edges produced. Etching techniques generally produce an edgethat is free of stress or defects and has good mechanical and electricalproperties. Etching applies no direct force to the material so nocrystal dislocations, crystal defects etc or other mechanical defectssuch as microcracks are formed. In addition the etching temperature isalso relatively cool and high temperature damage is avoided. For examplein the case of silicone plasma etching is typically 400° C. which iswell below those high temperature processes (above 800° C.) that cancause slip, recrystallisation and reformation of the substrate, as wellas damage to metal layers and alteration of doping profiles. Suchdefects cause major problems. In the case of glass or sapphire themechanical strength and robustness is reduced. In the case ofsemiconductors not only is the mechanical strength compromised but theelectrical properties particularly leakage current may be greatlyincreased. As such the resultant edge produced from edge trenching andcertain splitting methods is free of defects and mechanically andelectrically superior to the edge produced by prior art methodsparticularly where initial damage or high temperatures are used.

Fourthly, the improved electrical performance resulting from embodimentsof the present invention leads to a further advantage for electricaldevices: Edge termination structures are typically used in devices toisolate the poor quality defective edge from the virtually defect freeactive area. If the edge is of superior quality the size of the edgetermination structures may be reduced or even eliminated. This maygreatly reduce the device area required and hence significantly increasethe number of devices obtained from a wafer.

Fifth, as a result of the improved mechanical edge quality resultingfrom embodiments of the method according to the present invention therobustness is improved to a point that breakage either during splittingor subsequently in later processing is also reduced leading to animproved yield.

Sixth, the trenches formed in the surface(s) of the object wheresplitting is to take place, also provide a useful visual alignment aidfor the actual splitting. As a result, the splitting can be done easier,quicker, and under a better control, all contributing to a furtherimprovement in speed and edge quality at the end of the splitting.

Seventh, embodiments of the present invention are much more useful forsplitting thin materials than the prior art methods. Any “initialdamage” or mechanically stress inducing process such as high temperaturemay result in an uncontrolled fracturing and breakage of the material.For example for semiconductor devices “Thin wafers” typically below 220um are processed and it becomes increasingly difficult to cut suchwafers, particularly below thicknesses of 100 um. Embodiments of thepresent invention can, as a result of the process properties alreadydescribed, enable the cutting of such thin materials. Unlike the priorart method where the “initial damage” or high temperatures may break thethin wafers, trench etching in semiconductor wafers is a developedtechnology that can be well controlled and adjusted so as not to causeany breakage to thin wafers.

Finally, certain brittle splitting methods are not capable ofadditionally splitting the metallization layers found on the front orbackside of the material. The trench etching of embodiments of thepresent invention can cut through these layers as an inherent part ofthe process, thus providing a method of enabling certain splittingmethods which are not otherwise possible. For example in powersemiconductors the backside is frequently used as a contact for thedevice and relatively large currents may flow. This requires a stack ofdifferent metals of varying thicknesses and the cutting operation mustseparate these without undercutting or producing mechanical or chemicalstress that may result in peeling of this metallization or other suchproblems. The present invention allows both brittle and non brittlematerials to be cut as an inherent feature of the combined processes.

Summarizing the above, combining the trench etching technology with thebrittle material splitting methods, the brittle material splittingmethod of the present invention provides an efficient process withexcellent performance that facilitates many splitting options, produceshigh-quality edges with good mechanical and electrical properties, andis free from the defects typically obtained with mechanical sawing orprior art techniques requiring the “initial damage.”

FIG. 1 is a cross sectional view of an example object made of brittlematerial. The object 10 may be made of a single brittle material or acombination of different materials such as a processed Semiconductorwafer, composed of a brittle substrate and a number of other layers suchas oxide, metal, silicone glass, silicone nitride etc. The object is inone case flat and has two flat surfaces 11 and 12 opposite to eachother. A specific example of such an object is a processed semiconductorwafer made using silicon, germanium, or other material known in the art.The wafer has two surfaces typically called the front-side and theback-side, which correspond to the upper surface 11 and the lowersurface 12 in FIG. 1, respectively. Typically, these two surfaces areopposite to each other, with a distance of typically less then 250 um(although distances up to 500 um are also common.)

A first layer 14 may be formed below the lower surface 12, or back-side,of the wafer. Furthermore, a second layer 13 may be formed above theupper surface 11, or front-side, of the wafer in addition to any thatmay form part of the processed wafer object 10.

Each of layers 13, 14 may be a single metallization layer or passivationlayer, or may be a composite layer including at least one of ametallization and a passivation layer or isolation layer. Such sandwichstructure of different layers may serve as a wiring structure forsemiconductor devices integrated in the chips/dies forming the wafer.

FIG. 2 is a perspective view illustrating a part of the object ofbrittle material being split using a first embodiment of the method ofthe present invention. This first embodiment provides a method forsplitting the object into two separate pieces by firstly etching atrench in a surface of the object and then applying a splitting methodto the object to complete the splitting.

Specifically in this embodiment, in a first step, a trench 25 is etchedinto one of the two surfaces, here the upper surface 11, of the object10, thus defining a line 26 on the surface 11. Although not an absolutemust, in one case the line 26 originates from an end 27 of the surfaceand extends to another end (not illustrated) of the surface. The depthof the resultant trench is marked with H and the width thereof is markedwith W.

Any known etching technique may be used to form the trench. For example,in the case of semiconductor wafer dicing, a photolithographic processmay be used to define the location of the trench to be formed. Forinstance, a mask layer may be formed over the wafer to define a lineopening over the wafer. The defined location is then etched using aselective etchant. Any etchant known in the art may be used, forexample, a dry etchant such as one of the anisotropic dry plasma type, awet etchant such as a wet chemical, or else. A deep trenching plasmatechnique may be used in one case, as it produces a deep trench whichprovides certain benefits as to be discussed below. For the samereasons, a longer etching time may be used rather than to a shorter one.The trench profile is typically U shaped, as illustrated in the figure,but others such as V or bottle shaped are also possible, depending onthe different etching techniques used and etching conditions applied. Itshould be noted that the dimension and profile of the resulting trenchare not a big concern, because it is sufficient as long as the etchingcauses a weakening of the brittle material to the extent where the finalsplitting using conventional brittle material splitting methods ispossible. Nevertheless, a deep and narrow trench, that is, a highdepth-to-width ratio (H:W), is used in one case because it results in ahigh decrease in the brittle material strength while minimizing thewidth required for the final splitting. That is, a high depth-to-widthratio of the trenches enables an efficient splitting and achieves goodedge quality at the end of the splitting—for semiconductor wafers, goodedge quality also means good mechanical and electrical properties. Atypical high depth-to-width ratio is 5:1 or above. This ratiocorresponds to a trench depth of 5 μm and a trench width of 1 μm in asemiconductor wafer of a standard thickness, such as between 50 μm to200 μm, 100 μm for example.

After the trench 25 is etched, the object 10 is split into two pieces 21and 22 along the line 26 by using any of the brittle material splittingmethods known in the art, such as, splitting with mechanical force,scribing/abrasion methods, thermal splitting with or without a thermalshock process, laser ablation, etc. For instance, if a thermal splittingmethod is used, the area C of the object that is heated traverses alongthe trench 25 thus forming a crack 29 in the body of the object. Thecrack originates from the bottom of the trench and extends towards theother surface, here 12, of the object. Once the crack 29 completely goesthrough the object, the object is split into two pieces.

FIG. 3 is a perspective view illustrating a part of the object ofbrittle material being split under a second embodiment of the method ofthe present invention. This second embodiment provides a method forsplitting the object into two separate pieces by firstly etching atrench in one surface of the object, then etching another trench in theopposite surface of the object, whereas the second trench is in goodalignment with the first trench, and finally applying any of theconventional brittle material splitting methods to the object tocomplete the splitting.

Specifically in this embodiment, in the beginning, a trench 25 is etchedinto one of the two surfaces, for example, the upper surface 11, of theobject 10, thus defining a line 26 on the surface 11. Then, anothertrench 25′ is etched into the opposite surface 12 of the object 10. Anyknown etching technique as discussed earlier may be used to form thetrenches. However, it is important that the two trenches are wellaligned. Finally, the object 10 is split into two pieces 21 and 22 alongthe line 26 by using any of the brittle material splitting methods knownin the art. This final splitting step forms a crack 29 in the body ofthe object, the crack originating from the bottom of the first trench 25and extending towards the bottom of the second trench 25′. Of course,extending the crack in the opposite direction is also possible. Once thecrack 29 completely goes through the object, the object is split intotwo pieces.

FIG. 4 is a perspective view illustrating a part of the object ofbrittle material being split under a third embodiment of the method ofthe present invention. This third embodiment provides a method forsplitting the object into more than two separate pieces by firstlyetching a plurality of parallel trenches in at least one surface of theobject thus defining a plurality of lines on the surface, and thenapplying any of the conventional brittle material splitting methods tothe object to complete the splitting.

Specifically in this embodiment, in the beginning, a plurality oftrenches 25 ₁, 25 ₂, . . . , 25 n are etched into at least one of thetwo surfaces 11 and 12 of the object 10. It is possible that all thetrenches are etched into one surface, say 11. It is also possible toetch some of the trenches into one surface while the others into theother surface. These trenches 25 ₁, 25 ₂, . . . , 25 _(n) may be etchedin parallel. Any known etching technique as discussed earlier may beused to form the trenches. These trenches 25 ₁, 25 ₂, . . . , 25 _(n)define, correspondingly, a plurality of lines 26 ₁, 26 ₂, . . . , 26_(n) on the surface(s) 11. Each line, although not an absolute must,originates from an end of the surface and extends to another end of thesurface. After the trenches are etched, the object is split into morethan two pieces, 21, 22, 23, and so on, along the lines 26 ₁, 26 ₂, . .. , 26 _(n) by using any of the brittle material splitting methods knownin the art. Like previously discussed, the splitting is completed withthe formation and extension of cracks, here a plurality of cracks 29 ₁,29 ₂, . . . , 29 _(n) in the body of the object.

FIG. 5 is a perspective view illustrating a part of the object ofbrittle material being split under a fourth embodiment of the method ofthe present invention. This fourth embodiment provides a method forsplitting the object into more than two separate pieces by, to startwith, etching a first plurality of trenches 25 ₁, 25 ₂, . . . , 25 _(n)(only two are illustrated in the figure) in parallel in one surface, say11, of the object, thus defining a first plurality of lines 26 ₁, 26 ₂,. . . , 26 _(n) in parallel on the surface 11, then etching a secondplurality of trenches 35 ₁, 35 ₂, . . . , 35 _(n) (only two areillustrated in the figure) in parallel in the same surface thus defininga second plurality of lines 36 ₁, 36 ₂, . . . , 36 _(n) in parallel onthe surface 11. These two pluralities of lines cross each other with anangle in between, here illustrated as α. α may be any value greater than0°. For instance, α may be 90°, thus the two plurality of lines areperpendicular to each other. After the trenches are etched, the objectis split into more than two pieces, 21, 22, 23, 21′, 22′, 23′, 21′, 22″,23″, and so on, along the lines 26 ₁, 26 ₂, . . . , 26 _(n) and 36 ₁, 36₂, . . . , 36 _(n) by using any of the brittle material splittingmethods known in the art. The details of the etching and final splittingare similar to those discussed in earlier embodiments.

This fourth embodiment of the method is useful in some applications, forexample, semiconductor wafer dicing, wherein a wafer is expected to bediced into many smaller pieces in both an X axis and a Y axis. In thissituation, the method of the present invention has an advantage in thatit can define all the cutting lines in one single step. For instance, amask layer may be formed over the wafer to define a grid over the waferindicating the locations of the many trenches to be formed; the definedlocations are then etched at the same time. Thus, many trenches can beformed at one single step. This technique is much more efficient thanthe prior art method which has to make an initial damage to the objectat the start of each cut.

Although an angle α of 90° may be useful in cutting semiconductorwafers, a can also be any other value so as to enable cutting of wafersin directions other than the crystal alignment. This can be applied tocertain applications, such as wafer edge trimming.

FIG. 6 is a perspective view illustrating a part of the object ofbrittle material being split under a fifth embodiment of the method ofthe present invention. This embodiment is the same as the fourthembodiment, except that, during the trench etching step, a thirdplurality of trenches 25′₁, 25′₂, . . . , 25′_(n) (here only two areillustrated) are additionally etched in parallel in the other surface 12of the object. The third plurality of trenches are etched in goodalignment with the first plurality of trenches 25 ₁, 25 ₂, . . . , 25_(n), respectively, in the opposite surface 11.

FIG. 7 is a perspective view illustrating a part of the object ofbrittle material being split under a sixth embodiment of the method ofthe present invention. This embodiment is the same as the fifthembodiment, except that, during the trench etching step, a fourthplurality of trenches 35′₁, 35′₂, . . . , 35′_(n) (here only two areillustrated) are additionally etched in parallel in the same surface 12as the third plurality of trenches 25′₁, 25′₂, . . . , 25′_(n) (hereonly two are illustrated). This fourth plurality of trenches are etchedin good alignment with the second plurality of trenches 35 ₁, 35 ₂, . .. , 35 _(n) (here only two are illustrated), respectively, in theopposite surface 11.

FIG. 8 is a cross sectional view illustrating an object of brittlematerial being split under a sixth embodiment of the method of thepresent invention. As mentioned earlier, an object of brittle materialmay be a processed semiconductor wafer 10 with a metallization or otherlayer(s) layer 13 or 14 formed either above the upper surface 11 orbelow the lower surface 12, or a wafer with two or more suchmetallization or other layer(s) 13 and 14, one 13 formed above the uppersurface 11 of the wafer and the other 14 below the lower surface 12. Forexample in applying the method of the present invention to such asemiconductor wafer with additional metallization layer(s), the etchingstep will etch through the metallization layer(s) 13, 14 and furtherinto the surface(s) immediately below and/or below the etchedmetallization layer(s).

FIG. 9 is a cross sectional view of an example edge formed by the methodof the present invention. In the figure, E is an etched part of theedge, formed by the etching step. In particular, the etched part on theleft hand side is the result from a U-shaped trench, which may be formedby using a dry etchant of the anisotropic dry plasma type. The etchedpart on the right hand side is the result from a V-shaped trench, whichmay be formed by using an etchant such as a wet chemical. F is the partgenerated by the final splitting step using any of the conventionalbrittle material splitting methods. F is essentially a straight line.

The at least one line formed by etching may have the form of a closedloop (not depicted). This is in particular useful for wafer edgetrimming. In this case the line returns to its starting point, and thewafer is then split along this line.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat a variety of alternate and/or equivalent implementations may besubstituted for the specific embodiments shown and described withoutdeparting from the scope of the present invention. This application isintended to cover any adaptations or variations of the specificembodiments discussed herein. Therefore, it is intended that thisinvention be limited only by the claims and the equivalents thereof.

1. A method for splitting an object made of brittle material into atleast two pieces, the object having a first flat surface and a secondflat surface opposite to each other, said method comprising: etching atleast one trench in at least one of the surfaces so as to form at leastone line on the surface; and splitting the object into separate piecesalong the line.
 2. The method of claim 1, wherein the line starts fromone end of the surface to another end of the surface.
 3. The method ofclaim 1, wherein the line forms a closed loop.
 4. The method of claim 1,wherein the etching step etches a first plurality of trenches inparallel in the first surface of the object.
 5. The method of claim 4,wherein the etching step further etches a second plurality of trenchesin parallel in the first surface, the first and second plurality oftrenches forming an angle α in between, the angle α being greater than0°.
 6. The method of claim 5, wherein the angle α is 90°.
 7. The methodof claim 5, wherein the etching step further etches a third plurality oftrenches in parallel in the second surface of the object, wherein thefirst and third plurality of trenches are aligned.
 8. The method ofclaim 7, wherein the etching step further etches a fourth plurality oftrenches in parallel in the second surface, and wherein the second andfourth plurality of trenches are aligned.
 9. The method of claim 1,wherein the object is a processed semiconductor wafer, the first andsecond surfaces are respectively the upper and lower surfaces of thewafer.
 10. The method of claim 9, wherein at least one layer is formedon at least one of the first and second surfaces of the wafer andwherein the at least one trench is etched through the at least onelayer.
 11. The method of claim 10, wherein the at least one trench isetched through the layer and into the wafer.
 12. The method of claim 10,wherein the at least one layer is a metallization layer.
 13. The methodof claim 10, wherein the at least one layer is a passivation layer. 14.The method of claim 10, wherein the at least one layer is a compositelayer comprising at least one of the following layers: metallizationlayer, passivation layer, and isolation layer.
 15. The method of claim1, wherein the etching step uses a dry etch.
 16. The method of claim 15,wherein the dry etch is of the anisotropic dry plasma type.
 17. Themethod of claim 1, wherein the etching step uses a wet etch.
 18. Themethod of claim 1, wherein the trenches are etched to result in a highdepth-to-width ratio.
 19. The method of claim 18, wherein the highdepth-to-width ratio is equal to or above 5 to
 1. 20. The method ofclaim 1, wherein the splitting step uses mechanic force to split theobject into separate pieces.
 21. The method of claim 1, wherein thesplitting step uses an abrasion method to split the object into separatepieces.
 22. The method of claim 1, wherein the splitting step uses athermal splitting method to split the object into separate pieces. 23.The method of claim 1, wherein the splitting step uses a thermal shockprocess to split the object into separate pieces.
 24. The method ofclaim 1, wherein the splitting step uses a laser ablation method tosplit the object into separate pieces.
 25. The method of claim 1,wherein the brittle material is one of a glass comprising: glass,silicon, germanium, sapphire, quartz, ceramic and silicone carbide. 26.A system configured to split a processed semiconductor wafer comprising:the semiconductor wafer having at least one layer formed on a firstsurface of the semiconductor wafer; at least one trench etched in thefirst surface and through the at least one layer thereby forming a line;and means for splitting the semiconductor wafer into separate piecesalong the line.